1. Technical Field of the Invention
The present invention relates to a security system comprising an optical fiber serving as a key and having a Bragg gratings that provide for reflected light with a predetermined frequency spectrum which is detected and compared by a decoder to control the locking/unlocking of a locking mechanism.
2. Description of the Prior Art
Security systems comprising light sources, optical fibers having Bragg gratings, and electronic devices to detect for the predetermined frequency spectra reflected by the Bragg gratings are known, and one such system is described in U.S. Pat. No. 5,351,324 ('324), herein incorporated by reference. The '324 patent discloses an optical fiber placed in a container and located along the seals of the container so that if any one of the seals is disturbed or broken, the optical fiber is correspondingly disturbed or broken and its reflected frequency spectra is altered which is detected by the electronic devices to ascertain a security breach. The '324 patent, although serving well the needs of security for a container, does not address the needs of other users, such as an electronic lock used for industrial and domestic purposes and operated by an associated key.
Security systems using optical devices are also known and some of which are described in U.S. Pat. Nos. 4,079,605 ('605) and 4,369,481 ('481) and both of which are herein incorporated by reference. The '605 patent uses a card device to operate an electronic lock, whereas the '481 patent uses a key having reflective surfaces to operate an electronic lock. Whereas the card of the '605 patent is convenient in many ways, it does have a drawback in that it must be kept on person, such as in the wallet, and thus may be misplaced (not on the person) when actually needed. The key of the '481 patent although not normally being subjected to being misplaced, does have a drawback in that it requires the complementary lock receptacle to coact with light reflected off the surfaces of the key. This coaction limits one key to one receptacle, thereby, preventing one key to be used for multiple applications. It is desired that other types of key means be employed for optically operated electronic locks that allows for greater flexibility and convenience in their usage.
Accordingly, it is a primary object of the present invention to provide a key for optically responsive electronic locks that is convenient to use for multiple applications and which is not susceptible to being misplaced so that it may be used when needed.
It is yet another object of the present invention to provide a key for an optically responsive electronic lock that is formatted into unique patterns that are not easily duplicated, yet are easily verifiable for identification purposes.
It is still further an object of the present invention to provide for an optically responsive electronic lock having decode means that are commercially available so that the associated lock may be more economically acceptable by the industrial and domestic users.